D6h brakes coming on.

[4digger]

Hello. I have a cat d6h. It is a 3 spd powershift. Everything runs good when I first start it up and let it warm up about five mins. When I start to use it it's fine but after about 10 mins of running it if feels as if the brake are gradually comng on. You feel it every time you go from forward to reverse. Then the dozer will stop completely, when this happens you hear it going into gear but with the brakes being on it just won't move until I shut it down and restart and then it will move again for another 10 15 mins until the. Rakes come on again then you have to shut down and start up again to get it to move. Has anyone else had this problem? Thanks.

 

[hargrove]

Is your brake pedal sticking a little bit,especially if its an open cab.The bearings on the pedal cross shafts get rusty and the pedal won't return all the way.

 

[Construct'O]

If your decelrating when you shift back and fore what is your RPM when you decel.If you get below 600 RPM i believe the brakes will automaticly try to come on when you moving and may not release also.Check you RPM settings.Brakes also run off hydraulic pressure to release i believe also might check into that.Good luck

 

[Bob/Ont]

Hello. I have a cat d6h. It is a 3 spd powershift. Everything runs good when I first start it up and let it warm up about five mins. When I start to use it it's fine but after about 10 mins of running it if feels as if the brake are gradually comng on. You feel it every time you go from forward to reverse. Then the dozer will stop completely, when this happens you hear it going into gear but with the brakes being on it just won't move until I shut it down and restart and then it will move again for another 10 15 mins until the. Rakes come on again then you have to shut down and start up again to get it to move. Has anyone else had this problem? Thanks.

What you describe to me is an oil leak, possibly due to the brake control linkage as described. It also could be caused by debris falling into the linkage from the trans lockout lever to the park brake lever on the valve. You need a hose and 800psi gauge to connect to the brake valve and check this out. Brakes are released by the trans oil pressure.
Later Bob

 

[4digger]

ThAnks for the replies everyone. The brake isn't sticking in fact it moves free, I pulled up on it just to be sure. Also when things start to tighten up I tried not letting idle get so low before shifted into neutral and it wants to put you through the window. I'm going to put a gauge on it tomarrow. What kind of psi should I be seeing out of the trans in general and also what psi should be at the brake valve ?